Heretofore, as a partition panel designed to be installed onto a wall surface in a room, there has been known a sound absorption panel disclosed in the following Patent Document 1. This sound absorption panel comprises a front liner paper having a plurality of small holes, a back liner paper, and a paper honeycomb core interposed between the two liner papers. The paper honeycomb core has a honeycomb structure, and each of the front liner paper and the back liner paper is bonded to the paper honeycomb core.
However, the sound absorption panel of the Patent Document 1 has a problem of poor sound insulation performance. Specifically, since the entire front liner paper and the entire back liner paper are coupled together through the paper honeycomb core, it allows sound received by one of the front and back liner papers to be easily transmitted to the other through the paper honeycomb core.
Moreover, the sound absorption panel of the Patent Document 1, in which small holes are provided in the entire area of the front liner paper, has too high a sound absorption performance. This may extremely shorten reverberation time in a room and thereby give a strangeness or discomfort to a person in the room.
As a means to solve these problems, it is conceivable, instead of the installment of only the sound absorption panel disclosed in the Patent Document 1 onto a wall surface in a room, to alternately install the sound absorption panel of the Patent Document 1 and a partition panel having no sound absorption function, thus improving the sound insulation performance by the presence of the partition panel having no sound absorption function while generating the reverberation in the room so as to optimize the reverberation time in the room. This approach, however, generates a new problem of a loss of consistency of the wall surface.